JP2008275385A - Variable reluctance type resolver rotor and brushless motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a variable reluctance type resolver rotor capable of suppressing uneven deformation of the outside surface of a salient pole part caused by press fitting to a rotating shaft. <P>SOLUTION: The VR type resolver rotor 21 having a circular shape is press fitted to the rotating shaft 5 and fixed to the rotating shaft 5. The resolver rotor 21 is equipped with a plurality of salient pole parts 31 disposed at equal angle intervals in the circumferential direction, having each outside surface 31a which is axisymmetric with respect to a bisector of a central angle, and projecting to the outside in the radial direction; a hole part 32 into which the rotating shaft 5 is inserted; each press fitting part 34 formed on the hole part 32, and fixed to the rotating shaft 5 by being press-contacted with a circular part 5a on the outer circumferential surface of the rotating shaft 5; and each groove part 33 extending from the hole part 32 toward the outside in the radial direction. The position and the press fitting margin of each press fitting part 34 or the number and the positions of the groove parts 33 are set so that each strain dimension quantity appearing on the outside surface 31a of each salient pole part 31 by press fitting to the rotating shaft 5 becomes equal on each outside surface of all the salient pole parts 31. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a variable reluctance resolver rotor and a brushless motor.

  Conventionally, as a variable reluctance type (hereinafter also referred to as “VR type”) resolver rotor, for example, the one described in Patent Document 1 is known. The resolver rotor is fixed to the rotating shaft by press-fitting, and constitutes a resolver together with an annular resolver stator facing the outer surface (outer in the radial direction). The resolver stator has an excitation winding and an n-phase output winding in its slot. The outer surface of the resolver rotor has a non-circular shape so that the gap permeance with the resolver stator changes sinusoidally with respect to the rotation angle θ of the resolver rotor (rotating shaft).

Here, the resolver rotor has a protrusion that protrudes radially inward from the center hole thereof, and the protrusion is fitted into a recess formed on the outer peripheral surface of the rotating shaft when being pressed into the rotating shaft. It is positioned and fixed on the rotating shaft.
JP 2002-174535 A

  By the way, in the VR type resolver rotor of Patent Document 1, since the protrusion is fitted and fixed to the concave portion formed on the outer peripheral surface of the rotating shaft, the angular position where the protrusion is arranged at the time of press-fitting into the rotating shaft and the others Depending on the angle position, the outer surface of the resolver rotor may be deformed unevenly. Since the outer surface of the resolver rotor is formed into a highly accurate non-circular shape related to detection of the rotation angle θ, if such non-uniform deformation occurs, the rotation angle signal from each resolver (each output winding) Harmonic components that match the number of slots of the resolver stator that cause waveform distortion of the output signal of the line) are promoted and may significantly affect the detection performance.

  An object of the present invention is to provide a variable reluctance resolver rotor and a brushless motor that can suppress non-uniform deformation of an outer surface of a salient pole portion due to press-fitting into a rotating shaft.

  In order to solve the above problems, the invention described in claim 1 is an annular variable reluctance resolver rotor that is press-fitted into a rotating shaft and fixed to the rotating shaft, and is equiangularly spaced in the circumferential direction. A plurality of salient pole portions that are disposed and have an outer surface that is line-symmetric with respect to a bisector of the central angle and project radially outward, a hole portion through which the rotating shaft is inserted, and a hole portion A press-fit portion that is formed in pressure contact with the circular portion of the outer peripheral surface of the rotary shaft and is fixed to the rotary shaft; and a concave portion that extends radially outward from the hole portion, and press-fitting into the rotary shaft The position of the press-fit portion, the press-fitting allowance, or the number and position of the recesses are set so that the strain dimension amount appearing on the outer surface of each salient pole portion is the same on the outer surface of all the salient pole portions. The summary is as follows.

  According to the same configuration, the position of the press-fitting part, the press-fitting allowance, or the concave part of the concave part is set so that the distortion dimension amount appearing on the outer surface of all the salient pole parts becomes equal when press-fitting into the rotating shaft. By setting the number and position, it is possible to suppress uneven deformation of the outer surface of the salient pole portion due to press-fitting into the rotating shaft. Then, harmonic components that coincide with the number of slots of the resolver stator that cause waveform distortion of the output signal (rotation angle signal) of the resolver (VR type resolver) related to detection of the rotation angle of the rotation shaft can be suppressed. Therefore, the detection performance of the resolver can be improved.

  The invention according to claim 2 is characterized in that, in the variable reluctance type resolver rotor according to claim 1, the concave portion is arranged at an angular position of a central portion in the circumferential direction of each salient pole portion.

  According to the same configuration, the concave portion is arranged at an angular position of the central portion in the circumferential direction of the plurality of salient pole portions, and the shape of the VR resolver rotor is such that one salient pole portion is adjacent to the salient pole portion. Even if it is rotated to the position of the pole part, it appears to have the same shape. That is, the VR resolver rotor has symmetry (so-called rotational symmetry) with respect to the rotation center. Therefore, non-uniform deformation of the outer side surface of the salient pole portion due to press-fitting into the rotating shaft can be suppressed by a simple shape change due to the arrangement of the concave portion.

  The gist of the invention described in claim 3 is that, in the variable reluctance type resolver rotor according to claim 2, the press-fitting portions are provided symmetrically at both circumferential ends of the concave portions.

  According to this configuration, the press-fit portions are provided symmetrically at both circumferential ends of the respective recesses, so that uneven deformation of the outer surface of the salient pole portion due to press-fit to the rotation shaft is prevented. Further suppression can be achieved.

  The gist of the invention according to claim 4 is the variable reluctance resolver rotor according to claim 2, wherein the press-fitting portion is provided at a central portion in the circumferential direction between the adjacent concave portions.

  According to the same configuration, the press-fitting portion is provided in the central portion in the circumferential direction between the adjacent recesses, and thus the outer surface of the salient pole portion due to press-fitting into the rotating shaft is uneven. Deformation can be further suppressed.

  According to a fifth aspect of the present invention, in the variable reluctance resolver rotor according to any one of the second to fourth aspects, the through portions that are formed symmetrically on both sides in the circumferential direction of the concave portions and extend parallel to the axial direction are provided. It is summarized as having.

  According to this configuration, by having the through portion, deformation of the outer surface of the salient pole portion due to press-fitting into the rotating shaft can be mitigated. In addition, the through portion is formed symmetrically on both sides in the circumferential direction of each of the concave portions, thereby suppressing uneven deformation of the outer surface of the salient pole portion due to press-fitting into the rotating shaft. it can.

  The invention according to claim 6 is the variable reluctance resolver rotor according to any one of claims 2 to 5, wherein a plurality of magnetic steel plates are rolled at an angle between the adjacent salient pole portions. Is the gist.

  According to this configuration, the VR resolver rotor can absorb the uneven thickness of the magnetic steel sheet as a whole by rolling a plurality of magnetic steel sheets at an angle between adjacent salient pole portions. And errors during stacking can be reduced.

  The invention according to claim 7 is the variable reluctance resolver rotor according to claim 1, wherein the recess is an angular position of a central portion in the circumferential direction of any one of the plurality of salient pole portions. The press-fitting parts are arranged at respective angular positions of the circumferential ends of the concave part and the circumferential central part of the salient pole part other than the salient pole part where the concave part is arranged, and the concave part The press-fitting allowances of the press-fitting parts arranged at the respective angular positions of the central part in the circumferential direction of the salient pole parts other than the salient pole parts arranged are set to be equal to each other and arranged at both ends in the circumferential direction of the concave part. Further, the press-fitting allowance of the press-fitting part is set to be larger than the press-fitting allowance of the press-fitting part arranged at each angular position in the circumferential central part of the salient pole part other than the salient pole part in which the concave part is arranged. This is the gist.

  According to the present applicant, the change in the protruding length of the salient pole portion (outer surface) in the radial direction due to the press-fitting to the rotating shaft depends on whether or not the concave portion is disposed at the angular position. It has been confirmed. It has also been confirmed that the change in the protruding length of the salient pole part (outer surface) in the radial direction differs depending on the press-fitting allowance of the press-fitting part arranged at the angular position. According to the same configuration, the press-fitting allowances of the press-fitting portions arranged at the respective angular positions of the circumferential central portion of the salient pole portions other than the salient pole portions where the concave portions are arranged are set to be equal to each other, and The press-fitting margins of the press-fitting portions arranged at both ends in the circumferential direction of the concave portion are the press-fitting portions arranged at respective angular positions in the circumferential central portion of the salient pole portion other than the salient pole portion where the concave portion is arranged. Therefore, the change in the projecting length of the salient pole part (outer surface) to the outside in the radial direction due to the press-fitting to the rotating shaft can be made more uniform as a whole.

  According to an eighth aspect of the present invention, there is provided a variable reluctance resolver rotor according to any one of the first to seventh aspects, and an annular resolver stator disposed so as to face the variable reluctance resolver rotor in a radial direction. A brushless motor comprising a VR resolver, a stator, and a rotor that is disposed inside the stator and rotates integrally with the rotating shaft, wherein the recess is the variable reluctance resolver rotor with respect to the rotating shaft. It is a gist that it is a groove part for positioning in the circumferential direction.

  According to this configuration, the VR resolver rotor is detected by the VR resolver by positioning the VR resolver rotor in the circumferential direction with respect to the rotating shaft (for example, the magnetic pole center of the magnet of the rotor) by the recess (groove). The deviation between the rotation angle of the rotating shaft, that is, the rotation angle of the rotor of the brushless motor and the ideal rotation angle can be suppressed, and the occurrence of vibration and noise in the brushless motor can be suppressed. In particular, the detection performance of the VR resolver is improved by suppressing the non-uniform deformation of the outer surface of the salient pole portion of the VR resolver rotor due to the press-fitting into the rotating shaft. Generation of vibration and noise in the motor can be further suppressed.

  As described in detail above, the present invention can provide a variable reluctance resolver rotor and a brushless motor that can suppress non-uniform deformation of the outer surface of the salient pole portion due to press-fitting into the rotating shaft. .

(First embodiment)
Hereinafter, a first embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a sectional view showing a brushless motor 1 on which a VR resolver rotor according to this embodiment is mounted. The brushless motor 1 is assembled in a vehicular electric power steering apparatus whose main purpose is to assist a driver's steering operation, for example.

  As shown in FIG. 1, the brushless motor 1 includes an annular stator 4 in which a motor winding 2 is wound around a plurality of teeth 3 a of a stator core 3, and a rotating shaft 5 that is disposed inside the stator 4. A rotor 6 that rotates integrally and a VR resolver 7 that detects a rotation angle of the rotor 6 are provided.

  A motor case 10 of the brushless motor 1 includes a yoke housing 11 formed in a bottomed cylindrical shape and an end plate 12 that closes an opening 11 a of the yoke housing 11, and the stator 4 has an inner periphery of the yoke housing 11. It is fixed to the surface. The stator 4 generates a rotating magnetic field when three-phase (U, V, W phase) driving power is supplied to the motor winding 2.

  The rotor 6 has a rotating shaft 5 rotatably supported by bearings 13 and 14 provided on the bottom 11 b of the yoke housing 11 and the end plate 12, and is disposed inside the stator 4. The rotor 6 has a plurality of magnets (not shown) inside a cylindrical cover 6a for preventing magnet scattering. The rotor 6 rotates under the influence of a rotating magnetic field generated in the stator 4.

  The resolver 7 is disposed on the outer side of the resolver rotor 21 and a resolver rotor 21 as an annular VR resolver rotor that is press-fitted into the rotary shaft 5 and fixed so as to rotate integrally with the rotary shaft 5 (rotor 6). And an annular resolver stator 22.

  The resolver rotor 21 is formed by laminating magnetic steel plates, and includes a plurality (seven) salient pole portions 31 protruding outward in the radial direction, as shown in FIGS. These salient pole portions 31 are arranged at equal angular intervals in the circumferential direction, and have substantially arc-shaped outer surfaces (outer surfaces in the radial direction) 31a that are line-symmetrical with respect to the bisector of the central angle. ing. In FIG. 2, the central angle α and the bisector L are drawn on behalf of the salient pole portion 31 arranged on the upper right side.

  The resolver rotor 21 has a circular hole 32 through which the rotary shaft 5 is inserted at the center, and is radially outward from the hole 32 at the angular position of the circumferential center of each salient pole 31. It has the groove part 33 as a recessed part extended toward. Each groove part 33 penetrates in parallel with an axial direction in the aspect opened to radial inside. The groove 33 is for positioning the resolver rotor 21 in the circumferential direction with respect to the rotating shaft 5. For example, the resolver rotor 21 is configured such that the groove portion 33 is fitted to a protruding portion that protrudes radially outward from the circular portion 5a of the outer peripheral surface of the rotating shaft 5 to thereby provide a rotor 6 (for example, a permanent magnet) provided on the rotating shaft 5. The position in the circumferential direction with respect to the magnetic pole center) is determined.

  Further, the resolver rotor 21 has press-fit portions 34 formed in the hole 32 at positions on both ends in the circumferential direction of the groove portions 33. The press-fit portions 34 disposed at both ends in the circumferential direction of each groove portion 33 are symmetric (axisymmetric with respect to the bisector of the central angle). These press-fitting portions 34 have distances (diameters) from the center O to their tips, that is, press-fitting allowances, are set to be equal to each other. When the resolver rotor 21 is press-fitted into the rotary shaft 5, By doing so, the resolver rotor 21 is fixed to the rotating shaft 5.

  The resolver rotor 21 has a circular caulking portion 35 disposed between the outer surface 31 a of the salient pole portion 31 and the groove portion 33 at an angular position of the center portion in the circumferential direction of each salient pole portion 31. These caulking portions 35 are used for joining magnetic steel plates laminated in the axial direction constituting the resolver rotor 21.

  It goes without saying that the resolver rotor 21 having such a shape is line-symmetric with respect to the bisector of the central angle of each salient pole portion 31. The shape of the resolver rotor 21 is apparently the same even when one salient pole portion 31 is rotated to the position of the adjacent salient pole portion 31. That is, the resolver rotor 21 has symmetry (so-called rotational symmetry) with respect to the rotation center O. Therefore, when press-fitting into the rotating shaft 5, the deformation of the outer surface 31a of all the salient pole portions 31, for example, the change of the projecting length of the salient pole portion 31 (outer surface 31a) radially outward (FIG. 2B). ) Shows the direction of change with arrows. In other words, the position of the press-fit portion 34, the press-fit allowance, or the number and position of the groove portions 33 are set so that the strain dimensional amounts appearing on the outer side surfaces 31a of all the salient pole portions 31 are equal.

  The resolver stator 22 is formed by laminating magnetic steel plates. As shown in FIG. 2A, the resolver stator 22 is wound around the teeth 23a via a stator core 23 having a plurality (ten) of teeth 23a and a resin insulator 24. And a rotated resolver winding 25. Note that the resolver winding 25 is a two-phase excitation winding that outputs a single-phase excitation winding to which an excitation voltage is applied and an output signal having a different phase according to the rotation of the resolver rotor 21 based on the excitation of the excitation winding. It consists of output windings and is wound around teeth 23a at predetermined positions.

  In addition, a resolver connector 26 is provided integrally with the resolver stator 22. The resolver winding 25 is electrically connected to a control device (not shown) provided outside by connecting the resolver connector 26 to a connection connector 27a of a signal wiring 27 (see FIG. 1) extending from the outside. The control device detects the rotational position of the resolver rotor 21, that is, the rotor 6 of the motor 1, based on the output signal obtained from the output winding while exciting the excitation winding of the resolver winding 25, and the stator 4 (motor A three-phase drive power supply to be supplied to the winding 2) is generated.

  Next, a manufacturing mode of the resolver rotor 21 will be described. FIG. 3A is a plan view showing a magnetic steel plate 41 constituting the resolver rotor 21, and FIG. 3B is a side view showing a lamination mode of the magnetic steel plates 41. Needless to say, each magnetic steel plate 41 has the same shape as the resolver rotor 21 in plan view. FIG. 3A shows a state (posture) immediately after the magnetic steel plate 41 is punched from the material (material coil or the like) by press working. The magnetic steel plate 41 having rotational symmetry is shown in FIG. In order to clarify the angular position, a pattern is given to a predetermined angular range in the upper right and lower left for convenience. Each angle range corresponds to an angle range between the centers in the circumferential direction of adjacent salient pole portions 31 when the resolver rotor 21 is configured by stacking the magnetic steel plates 41.

  In FIG. 3B, the same pattern is attached according to each angle range shown in FIG. As shown in the figure, a plurality of magnetic steel plates 41 constituting the resolver rotor 21 are rolled up at an angle between adjacent salient pole portions 31 using the rotational symmetry. As a result, the uneven thickness of the magnetic steel plate 41 (material) is absorbed as a whole.

As described above in detail, according to the present embodiment, the following effects can be obtained.
(1) In the present embodiment, the position of the press-fit portion 34, the press-fitting allowance, or the press-fit portion 34 so that the amount of strain size appearing on the outer surface 31a of all the salient pole portions 31 becomes equal when press-fitted into the rotary shaft 5. By setting the number and position of the groove portions 33, non-uniform deformation of the outer surface 31a of the salient pole portion 31 due to press-fitting into the rotating shaft 5 can be suppressed. Then, a harmonic component (10th harmonic) that matches the number of slots (10) of the resolver stator causing the waveform distortion of the output signal (rotation angle signal) of the resolver 7 related to the detection of the rotation angle of the rotating shaft 5. Component) can be suppressed, and the detection performance of the resolver 7 can be improved. Thereby, the rotation angle of the rotor 6 of the brushless motor 1 can be detected more accurately, and the generation of vibration and noise in the brushless motor 1 can be suppressed.

  (2) In the present embodiment, the groove portion 33 is disposed at each angular position of the circumferential central portion of the plurality of salient pole portions 31, so that the shape of the resolver rotor 21 is one salient pole portion 31. Even if it is rotated to the position of the adjacent salient pole part 31, it appears to have the same shape. That is, the resolver rotor 21 has symmetry (so-called rotational symmetry) with respect to the rotation center O. Therefore, non-uniform deformation of the outer surface 31a of the salient pole portion 31 due to press-fitting into the rotating shaft 5 can be suppressed by a simple shape change due to the arrangement of the groove portion 33.

  (3) In the present embodiment, the press-fit portions 34 are provided symmetrically at both ends in the circumferential direction of the groove portions 33 (line symmetry with respect to the bisector of the central angle), so that Uneven deformation of the outer surface 31a of the salient pole portion 31 due to the press-fitting can be further suppressed.

  (4) In the present embodiment, the resolver rotor 21 has a non-uniform plate thickness of the magnetic steel plate 41 as a whole because the plurality of magnetic steel plates 41 are rolled at an angle between the adjacent salient pole portions 31. Can be absorbed, and errors in stacking can be reduced. A harmonic component that matches the number (seven) of salient pole portions 31 of the resolver rotor 21 that causes waveform distortion of the output signal (rotation angle signal) of the resolver 7 related to detection of the rotation angle of the rotating shaft 5. (Seventh harmonic component) can be suppressed, and the detection performance of the resolver 7 can be improved.

  (5) In the present embodiment, the rotation detected by the resolver 7 by positioning the resolver rotor 21 in the circumferential direction with respect to the rotary shaft 5 (for example, the magnetic pole center of the magnet of the rotor) by the groove 33. A deviation between the rotation angle of the shaft 5, that is, the rotation angle of the rotor 6 of the brushless motor 1 and the ideal rotation angle can be suppressed, and the occurrence of vibration and noise in the brushless motor 1 can be suppressed.

(Second Embodiment)
Hereinafter, a second embodiment of the present invention will be described with reference to the drawings. The second embodiment has a configuration in which only the press-fitting allowance, the number of grooves, and the position of the press-fitting portion of the resolver rotor of the first embodiment are changed, and thus detailed description of the same portions is omitted. To do.

  FIG. 4 is a plan view showing the resolver rotor 51 according to this embodiment. As shown in the figure, the resolver rotor 51 is directed radially outward from the hole 32 at the angular position of the circumferential central portion of any one of the plurality of salient pole portions 31. And a groove 52 as a recess extending in the direction. The groove part 52 penetrates in parallel to the axial direction in a manner of opening radially inward. The groove 52 is for positioning the resolver rotor 51 in the circumferential direction with respect to the rotating shaft 5. For example, the resolver rotor 51 is configured such that the groove 52 is fitted with a protrusion protruding outward in the radial direction from the circular portion 5a of the outer peripheral surface of the rotation shaft 5 to thereby provide a rotor 6 (for example, a permanent magnet) provided on the rotation shaft 5. The position in the circumferential direction with respect to the magnetic pole center) is determined.

  Further, the resolver rotor 51 has press-fit portions 53 formed in the hole portion 32 at positions on both ends of the groove portion 52 in the circumferential direction, and the periphery of the salient pole portion 31 other than the salient pole portion 31 in which the groove portion 52 is disposed. A press-fit portion 54 is formed in the hole 32 at each angular position in the center in the direction. The press-fit portions 53 disposed at both ends in the circumferential direction of the groove portion 52 are symmetric (axisymmetric with respect to the bisector of the central angle). The press-fit portions 54 disposed at the respective angular positions in the central portion in the circumferential direction of the salient pole portion 31 other than the salient pole portion 31 where the groove portion 52 is disposed are distances (diameters) R1 from the center O to the tip, that is, press-fit The bills are set equal to each other. Further, the distance (diameter) R2 from the center O to the tip of the press-fit portion 53 arranged at both ends in the circumferential direction of the groove portion 52 is set smaller than the distance (diameter) R1. In other words, the press-fitting allowance of the press-fitting parts 53 arranged at both ends in the circumferential direction of the groove part 52 is set larger than the press-fitting allowance of the other press-fitting parts 54. When the resolver rotor 51 is press-fitted into the rotary shaft 5, these press-fit portions 53 and 54 press the circular portion 5 a to fix the resolver rotor 51 to the rotary shaft 5.

  In the present embodiment, the positions of the press-fitting parts 53 and 54, the press-fitting allowance, or the number and positions of the groove parts 52 are the distortions that appear on the outer side surfaces 31a of all the salient pole parts 31 during press-fitting into the rotary shaft 5. The dimensions are set to be equal. Therefore, when press-fitting into the rotating shaft 5, the deformation of the outer surface 31a of all the salient pole portions 31, for example, the change in the projecting length of the salient pole portion 31 (outer surface 31a) radially outward (arrow in FIG. 4). The direction of change in FIG.

  In this embodiment also, the resolver rotor 51 is formed by laminating magnetic steel plates. However, since the resolver rotor 51 does not have symmetry (rotational symmetry) with respect to the rotation center O, it is needless to say that the magnetic steel plates constituting the same are laminated in the same phase.

As described above in detail, according to the present embodiment, the following effects can be obtained in addition to the effects (1) and (5) in the first embodiment.
(1) The change in the protruding length of the salient pole portion 31 (outer surface 31a) in the radial direction due to the press-fitting to the rotating shaft 5 varies depending on whether or not the groove portion 52 is disposed at the angular position. Further, the change of the protruding length of the salient pole portion 31 (outer surface 31a) in the radial direction differs depending on the size of the press-fitting allowance of the press-fit portions 53 and 54 arranged at the angular position. In the present embodiment, the press-fitting allowances of the press-fitting portions 54 arranged at the respective angular positions in the circumferential central portion of the salient pole portion 31 other than the salient pole portion 31 in which the groove portion 52 is arranged are set to be equal to each other. In addition, the press-fitting allowance of the press-fitting parts 53 disposed at both ends in the circumferential direction of the groove part 52 is set larger than the press-fitting allowance of the other press-fitting parts 54, so that the press-fitting to the rotary shaft 5 can be performed. The change of the protrusion length to the radial direction outer side of the said salient pole part 31 (outer surface 31a) can be made more uniform as a whole.

In addition, you may change the said embodiment as follows.
-In the said 1st Embodiment, as shown to Fig.5 (a), you may provide the circular through-hole 56 as a penetration part in the radial direction outer side of each press-fit part 34 regarding the center O. As shown in FIG. The through hole 56 is arranged on the outer side in the circumferential direction of each groove portion 33 so that a straight line L1 connecting the center O and the tip of the press-fit portion 34 passes through the opening, and penetrates in parallel to the axial direction.

  Further, as shown in FIG. 5B, a rectangular through groove 57 as a through part may be provided on the radially outer side of each press-fit part 34 with respect to the center O. The through groove 57 extends in the orthogonal direction from both side surfaces in the circumferential direction on the bottom surface side of each groove portion 33 so that the straight line L1 passes through the opening, and penetrates in parallel to the axial direction.

  In each of these modified embodiments, in addition to the same effects as those of the first embodiment, the salient pole portion 31 that accompanies press-fitting into the rotating shaft 5 is provided by having a through portion (through hole 56 or through groove 57). The deformation of the outer surface 31a can be mitigated. Further, the two through portions arranged in each groove portion 33 are formed symmetrically on both sides in the circumferential direction of each groove portion 33, so that the outer surface 31 a of the salient pole portion 31 accompanying the press-fitting to the rotating shaft 5. It is also possible to suppress uneven deformation.

  In the first embodiment, as shown in FIG. 6, instead of the press-fit portion 34, a press-fit portion 58 provided at the center in the circumferential direction between the adjacent groove portions 33 may be used. In this modified embodiment, in addition to the same effects as those of the first embodiment (1), (2), (4), and (5), the press-fitting portion 58 is provided at the central portion in the circumferential direction between the adjacent groove portions 33. As a result, the non-uniform deformation of the outer surface 31a of the salient pole portion 31 due to the press-fitting into the rotating shaft 5 can be further suppressed.

  Further, as shown in FIG. 7, also in this modified embodiment, a circular through hole 59 as a through portion may be provided on the outer side in the radial direction of each press-fit portion 58 with respect to the center O. The through hole 59 is disposed at the center in the circumferential direction between the adjacent groove portions 33 so that a straight line L2 connecting the center O and the tip of the press-fit portion 58 passes through the opening, and is parallel to the axial direction. To penetrate. By deforming in this way, deformation of the outer surface 31a of the salient pole portion 31 due to press-fitting into the rotating shaft 5 can be mitigated.

In each of the above embodiments, the number of salient pole portions 31 of the resolver rotors 21 and 51 may be other than “7”.
In each of the above embodiments, the resolver rotors 21 and 51 may be manufactured by sintering magnetic powder.

1 is a cross-sectional view of a brushless motor to which the present invention is applied. (A) and (b) are the top views which show the resolver rotor of 1st Embodiment, and its periphery structure. (A) (b) is a schematic diagram which shows the manufacture aspect of a resolver rotor. The top view which shows the resolver rotor of 2nd Embodiment, and its periphery structure. (A) (b) is a top view which shows the resolver rotor of a deformation | transformation form. The top view which shows the resolver rotor of a deformation | transformation form. The top view which shows the resolver rotor of a deformation | transformation form.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 5 ... Rotary shaft, 5a ... Circular part, 21 ... Resolver rotor, 31 ... Salient pole part, 31a ... Outer surface, 32 ... Hole part, 33, 52 ... Groove part as a recessed part, 34, 53, 54, 58 ... Press-fit part , 41 ... magnetic steel plate, 56, 59 ... through-holes as through-holes, 57 ... through-holes as through-holes.

Claims (8)

An annular-shaped variable reluctance resolver rotor that is press-fitted into a rotating shaft and fixed to the rotating shaft,
A plurality of salient pole portions disposed at equal angular intervals in the circumferential direction and having an outer surface that is line-symmetrical with respect to a bisector of the central angle and projecting radially outward;
A hole through which the rotating shaft is inserted;
A press-fit portion that is formed in the hole portion and press-contacts with a circular portion of the outer peripheral surface of the rotation shaft and is fixed to the rotation shaft;
A recess extending radially outward from the hole,
The position of the press-fitting part, the press-fitting allowance, or so that the strain size amount appearing on the outer side surface of each salient pole part by the press-fitting to the rotating shaft is equal on the outer side face of all the salient pole parts, or A variable reluctance resolver rotor characterized in that the number and position of the recesses are set. The variable reluctance type resolver rotor according to claim 1,
The variable reluctance resolver rotor, wherein the concave portion is disposed at an angular position of a central portion in the circumferential direction of each salient pole portion. The variable reluctance resolver rotor according to claim 2,
The variable reluctance resolver rotor, wherein the press-fitting portions are provided symmetrically at both circumferential ends of the concave portions. The variable reluctance resolver rotor according to claim 2,
The variable reluctance resolver rotor, wherein the press-fitting portion is provided in a central portion in a circumferential direction between the adjacent concave portions. In the variable reluctance type resolver rotor according to any one of claims 2 to 4,
A variable reluctance resolver rotor, characterized in that it has through-holes that are formed symmetrically on both sides in the circumferential direction of each recess and extend parallel to the axial direction. The variable reluctance resolver rotor according to any one of claims 2 to 5,
A variable reluctance resolver rotor, wherein a plurality of magnetic steel plates are rolled at an angle between adjacent salient pole portions. The variable reluctance type resolver rotor according to claim 1,
The concave portion is disposed at an angular position of a circumferential central portion of any one of the plurality of salient pole portions.
The press-fitting portions are arranged at respective angular positions in the circumferential direction both ends of the concave portion and the circumferential central portion of the salient pole portion other than the salient pole portion where the concave portion is arranged,
The press-fitting allowances of the press-fitting portions arranged at the respective angular positions of the circumferential central portion of the salient pole portions other than the salient pole portions where the concave portions are arranged are set to be equal to each other,
The press-fitting allowances of the press-fitting portions arranged at both ends in the circumferential direction of the concave portion are those of the press-fitting portions arranged at the respective angular positions of the circumferential central portion of the salient pole portion other than the salient pole portion where the concave portion is arranged. A variable reluctance resolver rotor characterized by being set to be larger than a press-fitting allowance. A VR resolver comprising: the variable reluctance resolver rotor according to any one of claims 1 to 7; and an annular resolver stator that is disposed so as to face the variable reluctance resolver rotor in a radial direction;
A stator,
A rotor disposed inside the stator and rotating integrally with the rotating shaft;
A brushless motor with
The brushless motor, wherein the recess is a groove for positioning the variable reluctance resolver rotor in the circumferential direction with respect to the rotating shaft.

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